Constipation is often the culprit and if it isn't diagnosed, children and their parents must endure an unnecessarily long, costly and difficult quest to cure nighttime wetting, say researchers at the Wake Forest Baptist Medical Center.
They found that 30 children and adolescents who sought treatment for bedwetting all had large amounts of stool in their rectums, despite the majority having normal bowel habits. After treatment with laxative therapy, 25 of the children (83 percent) were cured of bedwetting within three months.
"Having too much stool in the rectum reduces bladder capacity," said lead author Steve J. Hodges, M.D., assistant professor of urology at Wake Forest Baptist.
"Our study showed that a large percentage of these children were cured of nighttime wetting after laxative therapy. Parents try all sorts of things to treat bedwetting-from alarms to restricting liquids. In many children, the reason they don't work is that constipation is the problem," he said.
Hodges said the link between bedwetting and excess stool in the rectum, which is the lower five to six inches of the intestine, was first reported in 1986.
However, he said the finding did not lead to a dramatic change in clinical practice, perhaps because the definition of constipation is not standardized or uniformly understood by all physicians and lay people.
"The definition for constipation is confusing and children and their parents often aren't aware the child is constipated," said Hodges.
"In our study, X-rays revealed that all the children had excess stool in their rectums that could interfere with normal bladder function. However, only three of the children described bowel habits consistent with constipation," he explained.
Hodges explained that guidelines of the International Children's Continence Society recommend asking children and their parents if the child's bowel movements occur irregularly (less often than every other day) and if the stool consistency is hard.
"These questions focus on functional constipation and cannot help identify children with rectums that are enlarged and interfering with bladder capacity," said Hodges.
"The kind of constipation associated with bedwetting occurs when children put off going to the bathroom. This causes stool to back up and their bowels to never be fully emptied. We believe that treating this condition can cure bedwetting," he added.
The finding was reported online in the journal Urology.